In recent years, multifunctional cellular phones as represented by a multifunctional cellular phone terminal (smartphone) have been in widespread use. A multifunctional cellular phone terminal realizes various functions by various types of applications being installed. In many cases, such applications may have a function, such as the playback of radio or music data, these applications being incorporated into audio in the related art. In association therewith, a desire to use functions of such audio and the like, mounted on a multifunctional cellular phone terminal, in an onboard device has recently increased.
In this connection, a system has been known where a desired application is started up in a shorter period of time with less operation man-hours when portable appliances and onboard appliances are used in conjunction with each other (see, for example, Patent Document 1). In addition, a sound output control device has been known where a cellular phone connected to the sound output control device transmits audio data to the sound output control device in a streaming manner and the sound output control device automatically processes the transmitted audio data using an optimum application without manually selecting the audio data (see, for example, Patent Document 2).